Re: Going from simple to super CAPTCHA

On Tue, 2007-06-12 at 08:01 -0400, tedd wrote: > At 3:02 PM -0400 6/11/07, Robert Cummings wrote: > >OCR is extremely fast. I've done work in the past using OCR and while it > >was simple text in documents, the OCR program could extract the text > >from the image of a magazine page in about a second. For simplistic > >displays of text, or even only slight noise, the OCR will beat human > >hands down every time. > > > >Cheers, > >Rob. > > Rob: > > I was thinking about this the other day -- computers are fast and > people are generally slow. So, instead of making the time short, > examine how fast the answer was obtained. Immediate = computer; > delayed = human. > > Even an easy LETTER CAPTCHA takes time for a human, but a computer > can recognize and respond much quicker. > > I know, spammy can delay his bot's response, but it's just a > difference between computer/human to consider. > > For example, what if a LETTER CAPTCHA provided letters in a timed > sequence? Such as: > > A > > then .6 seconds (time delay random from .1 to 2 seconds) > > AS > > then 1.1 seconds > > ASD > > Would there be a consistent time difference between the way a > computer would read/respond to the letters as compared to a human? I > dunno, but it's food for thought. Human times are only predicatable beyond a certain speed. But computers can easily mimic a delay: <?php usleep( 500000 + rand( 1, 3000000 ) ); ?> Cheers, Rob. -- .------------------------------------------------------------. | InterJinn Application Framework - http://www.interjinn.com | :------------------------------------------------------------: | An application and templating framework for PHP. Boasting | | a powerful, scalable system for accessing system services | | such as forms, properties, sessions, and caches. InterJinn | | also provides an extremely flexible architecture for | | creating re-usable components quickly and easily. | `------------------------------------------------------------'